The Effects of Vegetable Preloading on Postprandial Glycemia, Insulinaemia and Gastric Emptying (APRE)

The Effects of Vegetable Preloading on Postprandial Glycemia, Insulinaemia and Gastric Emptying in Healthy Adults: A Randomized Cross-over Trial

The objective of this study is to investigate the importance of leavy vegetable preloading on the postprandial glycaemic and insulinemic response in human subjects when consumed a specific amount of digestible carbohydrate from Russet Burbank potatoes source.

Study Overview

• Status: Active, not recruiting
• Conditions: Postprandial Hyperglycemia; Insulin High
• Intervention / Treatment: Other: Co-ingestion; Other: 0 min preload; Other: 5 min preload; Other: 10 min preload; Other: 15 min preload; Other: 20 min preload; Other: Spinach only / 10 min preload; Other: Canola oil only / 10 min preload

Detailed Description

The proposed research is part of strategies to manipulate postprandial glycemia and generate weight-control-related benefits, such as promoting satiation. Literature has shown pre-loading caloric nutrients can change postprandial glycemia, but the mechanism is unclear. The investigators hypothesize that a small number of nutrients released in the small intestine can initiate physiological changes and develop feedback control to delay gastric emptying, leading to the delay in digestion of glycemic carbohydrates and the consequent moderate glycemic responses. The investigators propose to use potatoes as the testing glycemic carbohydrates, and the pre-load foods are green vegetables. The investigators will be testing the optimal preload time to achieve the highest control of glycemic response as well as the strongest effect in satiety induction. In addition, green vegetables will be consumed with or without a preload fat enhancer (canola oil) to investigate the mechanism behind significant preload compositions. Healthy adults will be instructed to eat the leafy vegetables first (with or without canola oil), followed by the potato foods (i.e., mashed potatoes). The measurement is the gastric emptying time, blood sugar concentration, insulin, and an appetite-related gut hormone GLP-1. In order to monitor gastric emptying using a non-invasive approach, a popular breath test used in children and a hydrogen breath test will be used to present the change of gastric emptying and the level of gut fermentation.

Results will demonstrate the mechanism of the impact of pre-loading nutrients on the digestion of glycemic carbohydrates. The goal is to eliminate the negative influence of glycemic carbohydrate consumption. Instead, to generate health benefits from dietary carbohydrates.

• Study Type: Interventional
• Enrollment (Actual): 24
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Singapore
  • Singapore, Singapore, 117599
    • Clinical Nutrition Research Centre (CNRC)

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Normal body mass index (18.5 kg/m2 to 24.9 kg/m2), weight >/= 45 kg
• Normal blood pressure </=120/80 mmH
• Fasting blood glucose of <5.6 mmol/l
• Able to provide written informed consent before participating in the study.
• Able to communicate adequately to comply with the requirements of the entire study, i.e., able to eat test meal and provide breath samples.

Exclusion Criteria:

• Smokers.
• Individuals with any metabolic diseases (such as diabetes, hypertension etc).
• Individuals with known glucose-6-phosphate dehydrogenase deficiency (G6PD deficiency).
• Individuals with medical conditions and/or taking medications known to affect glycaemia (glucocorticoids, thyroid hormones, thiazide diuretics).
• Individuals who take any prescribed medication or dietary supplements which may interfere with the study measurements.
• Individuals who have any major organ dysfunction (eg. cardiovascular, respiratory, hepatic, renal, gastrointestinal) that may influence taste, olfaction, appetite, digestion, metabolism, absorption or elimination of test foods, nutraceutical or drug.
• Individuals with history of malabsorption due to mucosal disease, pancreatic disease, or other causes.
• Individuals with history of gastrointestinal disease or surgery (excludes appendectomy, hernia repair and anorectal disorders).
• Individuals who are allergic/intolerant to any of the test foods to be administered, or any of the following common food and ingredients: eggs, fish, milk, peanuts, tree nuts, shellfish, soya, wheat, gluten, cereal, fruits, dairy products, meat, vegetable, sugar and sweetener, natural food colourings or flavourings, sulphites etc.
• People who intentionally restrict food intake.
• People who consume excessive 13C rich products such as corn, sugar beet and pineapple.
• Individuals who partake in sports at the competitive and/or endurance levels
• Individuals who have any known chronic infection or known to suffer from or have previously suffered from or is a carrier of Hepatitis B Virus (HBV), Hepatitis C Virus (HCV), Human Immunodeficiency Virus (HIV).
• Individuals who is a study team member or an immediate family of any study team member.
• Individuals who consume Excessive alcohol: consuming >/= 6 alcoholic drinks per week.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

10

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Control (All 24 participants); Subjects consume 300 g of Russet Burbank mashed Potatoes
Experimental: Co-ingestion (All 24 participants); Subjects co-ingest both (300 g mashed potatoes) and (200 g baby round spinach supplemented with canola oil) in the same time.	Other: Co-ingestion; Subjects co-ingest both (300 g mashed potatoes) and (200 g baby round spinach supplemented with canola oil) in the same time.
Experimental: 0 min preload (meal sequence) (10 participants); Subjects consume 200 g baby round spinach supplemented with canola oil first, then directly consume 300 g of mashed potatoes.	Other: 0 min preload; Subjects consume 200 g baby round spinach supplemented with canola oil first, then directly consume 300 g of mashed potatoes.
Experimental: 5 min preload (10 participants); Subjects consume 200 g baby round spinach supplemented with canola oil first, wait 5 minutes, then consume 300 g of mashed potatoes.	Other: 5 min preload; Subjects consume 200 g baby round spinach supplemented with canola oil first, wait 5 minutes, then consume 300 g of mashed potatoes.
Experimental: 10 min preload (10 participants); Subjects consume 200 g baby round spinach supplemented with canola oil first, wait 10 minutes, then consume 300 g of mashed potatoes.	Other: 10 min preload; Subjects consume 200 g baby round spinach supplemented with canola oil first, wait 10 minutes, then consume 300 g of mashed potatoes.
Experimental: 15 min preload (10 participants); Subjects consume 200 g baby round spinach supplemented with canola oil first, wait 15 minutes, then consume 300 g of mashed potatoes.	Other: 15 min preload; Subjects consume 200 g baby round spinach supplemented with canola oil first, wait 15 minutes, then consume 300 g of mashed potatoes.
Experimental: 20 min preload (10 participants); Subjects consume 200 g baby round spinach supplemented with canola oil first, wait 20 minutes, then consume 300 g of mashed potatoes.	Other: 20 min preload; Subjects consume 200 g baby round spinach supplemented with canola oil first, wait 20 minutes, then consume 300 g of mashed potatoes.
Experimental: Spinach only /10 min preload (All 24 participants); Subjects consume 200 g baby round spinach supplemented with canola oil first, wait 10 minutes, then consume 300 g of mashed potatoes.	Other: Spinach only / 10 min preload; Subjects consume 200 g baby round spinach WITHOUT canola oil first, wait 10 minutes, then consume 300 g of mashed potatoes.
Experimental: (Spinach + Canola oil) 10 min preload (All 24 participants); Subjects consume 200 g baby round spinach WITHOUT canola oil first, wait 10 minutes, then consume 300 g of mashed potatoes.	Other: 10 min preload; Subjects consume 200 g baby round spinach supplemented with canola oil first, wait 10 minutes, then consume 300 g of mashed potatoes.
Experimental: Canola oil only / 10 min preload (All 24 participants); Subjects consume 20 g of canola oil first, wait 10 minutes, then consume 300 g of mashed potatoes.	Other: Canola oil only / 10 min preload; Subjects consume 20 g of canola oil first, wait 10 minutes, then consume 300 g of mashed potatoes.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postprandial blood glucose	Blood samples are taken at baseline, 15, 30, 45, 60, 90, 120, 150 and 180 minutes. Glucose levels are tested in the serum using cobas c311 analyzer.	up to 3 hour (180 minutes) after test meal consumption
Postprandial blood Insulin	Blood samples are taken at baseline, 15, 30, 45, 60, 90, 120, 150 and 180 minutes. Insulin levels are tested in the serum using cobas e411 Immunoanalyzer.	up to 3 hour (180 minutes) after test meal consumption
Postprandial Glucagon Like Peptide -1 Total (GLP-1)	Blood samples are taken at baseline, 15, 30, 45, 60, 90, 120, 150 and 180 minutes. GLP-1 levels are tested in the plasma using GLP-1 Total ELISA kit (EZGLP1T-36K)	up to 3 hour (180 minutes) after test meal consumption

Collaborators and Investigators

• Sponsor: Singapore Institute of Food and Biotechnology Innovation
• Collaborators: Alliance for Potato Research and Education
• Investigators: Principal Investigator: Amy Lin, PhD, Senior Principal Scientist I at Singapore Institute of Food and Biotechnology Innovation

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2023
• Primary Completion (Estimated): November 30, 2024
• Study Completion (Estimated): September 19, 2025

Study Registration Dates

• First Submitted: October 10, 2024
• First Submitted That Met QC Criteria: October 11, 2024
• First Posted (Actual): October 15, 2024

Study Record Updates

• Last Update Posted (Estimated): November 8, 2024
• Last Update Submitted That Met QC Criteria: November 6, 2024
• Last Verified: November 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Metabolic Diseases; Glucose Metabolism Disorders; Hyperglycemia
• Other Study ID Numbers: 2021-095

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: According to the approved IRB# 2021-095, all IPD are owned by Singapore Institute of Food and Biotechnology Innovation (SIFBI)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No